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Heart Disease - Diagnosing Congestive Heart Failure (CHF)


Because congestive heart failure (CHF) typically results from other cardiac diseases, most commonly coronary artery disease, asymptomatic patients are not usually screened for CHF. When patients present symptoms that may indicate CHF, diagnostic tests will be performed to determine the cause. In some cases, results from coronary artery disease screening methods (blood cholesterol tests, blood pressure measurements, stress tests, etc.) may also indicate CHF and warrant further examination.

Early symptoms of CHF may include:

  • Fatigue
  • Dyspnea (shortness of breath)
  • Wheezing or hoarseness

Other noticeable symptoms include:

  • Heart palpitations
  • Swollen ankles and legs
  • Weight gain (due to fluid build-up)

Depending on the extent of CHF, patients may also have other complications including:

  • an abnormal heart murmur
  • pulmonary congestion
  • arrhythmia (irregular heartbeat)
  • hypertrophy (enlarged heart)
  • tachycardia (accelerated heartbeat)
  • kidney or liver problems

Diagnosing CHF typically begins with a physical exam, including careful documentation of the patient’s medical and personal history of heart problems (i.e., atherosclerosis—narrowing of arteries, coronary artery disease, history of CHF, congenital heart disease).

To help diagnose heart failure and gauge treatment, the New York Heart Association (NYHA) functional classification system or similar criteria may be used:

Class Description
Class I (Mild) No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea (shortness of breath).
Class II (Mild) Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity results in fatigue, palpitation, or dyspnea.
Class III (Moderate) Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes fatigue, palpitation, or dyspnea.
Class IV (Severe) Unable to carry out any physical activity without discomfort. Symptoms of cardiac insufficiency at rest. If any physical activity is undertaken, discomfort is increased

Diagnostic Tests Used to Confirm CHF

  • Chest x-ray: A chest x-ray images the heart and surrounding thoracic anatomy, shows heart size and shape and reveals whether the heart is misshapen or enlarged due to disease. Abnormal calcification (hardened blockage due to cholesterol build up) in the main blood vessels and fluid in the lungs (possible indication of CHF) can also be seen. Chest x-rays can also be used to image pacemakers and artificial heart valves to check for correct positioning.
    • Electrocardiogram (ECG or EKG): An electrocardiogram is a graphical record of the electrical activity of the heart. A normal ECG, in most cases, rules out the presence of other cardiac diseases. An abnormal ECG indicates the presence of a cardiac disease and further investigations are performed. An ECG can be beneficial in detecting the disease and sometimes even the extent of the disease.
    • Echocardiogram (heart ultrasound): This diagnostic technique is an excellent tool to provide details of the cardiac structures – vessels, valves, and muscle. Echocardiography is a non-invasive exam in which images are acquired and viewed in real time without the use of radiation. Echocardiography is often useful in studying the beating heart and provides some information on functional abnormalities of the heart wall, valves and blood vessels. Echocardiography with Doppler is used to measure blood flow across valves, across septal defects (shunts), extent of regurgitations, etc. Color flow mapping capability is extremely useful in the detection of shunts. Abnormal operation of the valves can be detected by studying the opening and closing function versus normal valve function. Echocardiography may also be used to study congenital heart defects such as a septal defect (a hole in the wall that separates the two chambers of the heart).
    • Stress test: A stress test involves taking an ECG before, during and a treadmill workout to detect possible heart disease and/or damage, including the extent of coronary artery disease. However, false positive results are possible with stress tests.
    • Nuclear cardiology: Nuclear cardiology (also called radionuclide scanning or stress thallium imaging) allows visualization of the function of the heart. Myocardial perfusion imaging is the most common nuclear cardiology test to assess coronary artery disease. This noninvasive test can identify and quantify areas of inadequate blood supply within the myocardium (heart muscle), detect scaring of the myocardium, and assess the heart's pumping function. Nuclear cardiology is a cost-effective tool to help determine which patients are candidates for coronary angiography, revascularization, or coronary artery bypass surgery. Nuclear cardiology is also useful to monitoring the effectiveness of coronary revascularization or bypass surgery.
  • Coronary angiography: The procedure, performed in a cardiac catheterization laboratory, is minimally invasive and involves placing a catheter in a major blood vessel and injecting a dye (radio-opaque material) to create an image of the heart and coronary arteries. Angiography is excellent for imaging blockages in the coronary vessels. Angiography can also image the beating heart in real time and may be useful in evaluating the function of the heart chambers. Angiography is often used for diagnosing heart disorders, but is also a valuable tool for guiding therapeutic treatment of the coronary arteries (e.g. angioplasty). In addition to diagnosing coronary artery disease, angiography is useful for diagnosing or treating children with congenital heart diseases and is also used during pacemaker implantation to help position the pacemaker leads.

    • Updated: August 2006